1. Field of the Invention
The present invention relates to a cooking heater for heating an object to be cooked that is placed in a cooking space of the cooking heater through an open door with the door automatically opening/closing.
2. Description of the Related Art
Various cooking heaters having a front door have been hitherto proposed. Aside from such heaters, a sliding-drawer type cooking heater has been proposed. The sliding-drawer type cooking heater is suitable for a relatively large structure. Hence, the sliding-drawer type cooking heater has been used as a part of a built-in kitchen. In parallel with the diversification and unitization of cooking devices, there has been proposed a cooking device that integrates a cooktop, a drawer-type microwave oven, and an electric oven.
To give an example of the sliding-drawer type cooking heater, there is a heater having a sliding function in which a bottom that is continuous with a front door smoothly slides over a heater main body and the bottom is moved together with the door by transmitting a torque of a motor provided in the heater main body by use of a transmitting device such as a rack and pinion mechanism (see Japanese Unexamined Patent Application Publication No. 3-45820 (p. 3, 1.5 in the upper left column'to 1.16 in the upper right column, FIGS. 2 to 4). A door opening/closing mechanism includes a latching device for keeping the door closed, a door opening/closing switch, and a controlling circuit for rotating a motor to open/close the door in response to a signal from the door opening/closing switch. When the door opening/closing switch is pressed, the latch is automatically opened, and in addition, the door starts opening/closing together with the door by means of a driving force of the motor.
As another example of the sliding-drawer cooking heater, there is a cooking heater having a drawer for receiving an object to be heated, which is provided slidably over a heater main body. When the heater detects that the drawer is pulled out, an electromagnet provided on the bottom surface of the heater main body is excited so as to attract a metal turntable supporting a heating device (see Japanese Unexamined Patent Application Publication No. 6-109257 (paragraph [0010], FIG. 1). The electromagnet attracts the metal turntable at a timing when the drawer is pulled out, so the drawer is prevented from coming off a kitchen counter and toppling on account of losing the weight balance.
As still another example of the sliding-drawer type cooking heater, there is a microwave oven having a sliding-drawer type table (see Japanese Unexamined Patent Application Publication No. 11-237053, paragraphs [0030] to [0035], FIG. 1). In this microwave oven, an open-topped heating container can be pulled out from a main-body case, and the heating container and a cover portion are provided on the main-body case for covering the container to confine the microwaves and define a heating chamber. This electric oven prevents a leakage of radiowaves owing to the provision of a choke cavity between the periphery of the opening of the heating container and the cover portion opposite to the periphery.
The applicants of the present invention propose a cooking heater having a drawer which can be pulled out from a heater main body, for accommodating an object to be heated, (Japanese Patent Application Nos. 2004-7384 and 2004-7385). According to the heater proposed in Japanese Patent Application No. 2004-7384 by the applicants of the present invention, it is possible to reduce a manufacturing cost without requiring expensive parts and material of high heat resistance and flame resistance. In addition, the heater is structured such that a sliding mechanism is not subjected to the radiowaves applied to the heating chamber, thereby eliminating the danger of electrical discharge due to the application of the microwaves. According to the heater proposed in Japanese Patent Application No. 2004-7385, it is possible to prevent the occurrence of a situation in which vibrations from an opening/closing operation are transmitted to an object being heated, resulting in ejection of an overheated liquid in a steam form at a dash due to impacts resulting from the vibrations, whereby a user is scalded. Further, it is possible to control a moving speed of the door to prevent an object being heated from falling down or prevent a liquid component from overflowing due to the impact applied during the opening/closing operation. Further, the moving mechanism can be obtained without requiring expensive parts or material having a high heat resistance and flame resistance, thereby saving the manufacturing cost. In addition, the heater is structured such that a sliding mechanism is not subjected to the radiowaves applied to the heating chamber, thereby eliminating the danger of electrical discharge due to the application of the microwaves.
In the sliding-drawer type cooking heater having an automatically opening/closing door, there is a danger that a user's finger or hand could be accidentally pinched between the door and a heater main body at the time of opening the door. There is another danger that a user could get hit by the door in the course of opening the door. If the door opens/closes at a fixed speed that is low enough to ensure safety even in the case where the user's finger or hand is pinched between the door and the main body or the user gets hit by the door in order to eliminate the above danger, this slow opening/closing operation may irritate a user rather than serve the user.
To that end, in the cooking heater having an automatically opening/closing door, there is a problem remaining to be solved, in terms of preventing the danger inherent in the automatic opening/closing operation.